1. Field of the Invention
This invention relates to lockable adjustment mechanisms for adjustable components. The invention has been conceived in relation to flow control valves, and will primarily be discussed in relation thereto but it is to be understood that it is applicable to a wide range of adjustable components.
2. Description of the Prior Art
Flow control valves typically have an adjustment member extending therefrom which may be part of a needle valve or a piston arrangement, for example, the adjustment mechanism being cooperable therewith in order to set the valve as required, and also being lockable so as to prevent inadvertent interference with a selected setting. Known adjustment mechanisms have comprised a special two-part adaptor, a first part thereof being screwed or otherwise attached to the valve, and a second part thereof adapted to receive the lockable adjuster The second part comprises an adjustment member for the valve which replaces the normal adjustment member of the valve. Thus the replacement adjustment member has to be tailored to the type of valve being converted and hence is relatively expensive. As will be appreciated from the foregoing, the disadvantage of this known arrangement is that the adaptor adds considerably to the basic cost of the adjustment mechanism and furthermore, the size of adaptor has to be selected to suit the component to which the lockable adjustment mechanism is to be fitted. The adaptor also increases the overall length of the adjustment mechanism and this can be problematical if space is at a premium. Furthermore, the fitting time is relatively high in view of the fact that the normal valve adjustment member has to be replaced.
The object of the present invention is to provide a universal lockable adjustment mechanism for adjustable components and to reduce the cost of manufacture thereof.